Seal for electrolytic condensers



Aug. 1933- J. E. LILIENFELD SEAL FOR ELECTROLYTIC CONDENSERS Filed July 25, 1929 R O T N E V m JUL/us [00m A IL mwmem A'r'rohNEY Patented Aug. 1, 1933 1,920,799

UNITED STATES PATENT OFFICE SEAL FOR ELECTROLYTIC CONDENSERS Julius Edgar Lilienfeld, Winchester. Mass'., assignor to The Ami-ad Corporation, Medford Hillside, Mass., a Corporation of Ohio Application July 25, 1929. Serial No. 380,844

Claims. (o1.175 315) The invention relates to electrolytic condensers through-an electrode or electrodes arranged to be embodying a metallic shell for retaining the elecclamped thereto in any well-known or special trolyte, said shell constituting one of the elecmanner to be sealed by the base of the cap. trodes of the condenser, and a suitable cover Moreover, there is provideda vent openinginthe 5 member for sealing the condenser and through disk which is arranged to cooperate with a rup- 60 which the other electrode or electrodes are turable portion of the base of the cap and this brought; and the invention relates more espemay be accomplishedmanually or automatically, cially to the novel construction and arrangement as will hereinafter be more fully set forth. of thi e Ii b I The nature of the invention, however, will best 10 As heretofore constructed, these sealing membe understood when described in connection with 5 bers have not at all times maintained a sufiicien'tly the accompanying drawing, in which: tight seal; and it is the object of the present in- Fig. 1 is a front elevation and part vertical vention to provide a novel sealing member which section of an electrolytic Condenser Co pris will at all times insure a tight seal and which "the novel type of cover member.

sealing member, moreover, requires less parts and Fig. 2 is a vertical section of the novel cover 70 simplifies the installation of the electrodes, A member with electrodes removed. further object of the invention resides in the Fig. 3 is a similar view illustrating a modificaconstruetion of a sealing member which enables tion. i the cells to be transported initially with vent Fig. 4 is a plan view and Fig.5 a fragmentary opening sealed as well as to provide for the convertical section illustrating the novel cover mem- 75 venient and ready opening of the vent when the her provided with means for rupturing the porcell is placed in operation. A still further object, tion of the cap element of the cover member; of the "invention resides in means whereby this and illustrates, also, the arrangement wherein venting operation may be accomplished auto; the disk element is composed of metal.

matically and, also, whereby there will be pro- Fig. 6 is an'enlarged vertical section of the 80 vided at all times an ample vent for accommodatmetal vent cap employ'ed'in connection with the ing unusual gas pressures whichmay develop in cap member. the condenser under certain conditions. Referring to the drawing, 10 designates a cell In carrying out the invention, the usual shell formed, for example, of a metal shell comprising for retaining electrolyte is provided, as of a metal one of the electrodes of the condenser and de- 85 shell having also the rolled-in bead or inwardly. signed to retain 'a'suitable electrolyte, the said directed ledge for supporting the cover member shell being provided with an inw d y rolled bead which is held in place by crimping or turning over or ledge providing a support 11. This support is the upper edge of the shell over said cover designed to carry a cap member, hereinafter member. i more fully described, which is held thereto by 90 This cover member is designed to support the turning inwardly or crimping over the outer edge other electrode or electrodes of the condenser 12 of "the metal shell, as indicated. The cap and, in accordance with the invention, is commember aforesaid is designed to carry one or posed of elements-@118 a rigid eleme t o more electrodes 13 extending into the electrolyte;

s of su at material metal, While t and where a plurality of these electrodes are em- 95 other consists of a cap of insulating material of -p1oyed a grounding tab 14 is connected with the a resilient or elastic nature forming a type electrode shields 14, and arranged to be conseal in eontradistinction to the usual type of sealv nested in turn with the metal Shell '0 (at negafl embodymg .nultlphclty of 1nd1v1.dua1 gaskets tive or zero potential) as in extending the tabs The cap is designed to envelop entirely the bottom and sides of the rigid disk and is provided to the top of the cap rather than turning the same under the crimping edge 12.

with an in-turned flange extending overthe top or outer face of said disk and designed to coact P P b composed of a single rigid disk with individual washers for with the crimped edge of the shell to clamp the. entire cover member between said edge and the sealmg the top of the contamer and of a Separate 105 inwardly directed support of the shell so as to device for Venting the container 1 the 9- form a, seal betwe n d crimped edge and t trodes, as has been the practice heretofore, comfiange, thereby securely sealing the entire conp s tW elements Yl one e e 15 denser. Registering perforations are provided b i of rigidmaterial as of insulation respectively in the disk and cap to admit theremetal, in the latter instance provision being' made to insulate the electrodes therefrom as silient or elastic material and having insulating properties, for example, rubber. This can covers entirely the inner face or bottom of the disk 15 and is brought over the sides of said disk with an inwardly extending flange 17 which fits tightly over the top of the disk and is adapted to coact with the crimped-over edge 12 of the shell to clamp the cover member between said edge and the support 11 to effect thereby a seal of the condenser between the said edge and the flange.

In addition, suitable perforations 18 are provided in the disk 15 to register withpe'rforations 19in the bottom of the cap to admit an electrode through the cover member into the cell. It will be appreciated that this cap affords in an integral unit the gasket for sealing the top of the container, the gasket for the electrodes and a vent; andthat when using an insulating rigid disk therewith no additional washer or any other expedient is necessary. A secure seal may thus be effected for the electrodes by providing. an electrode with the flange, 20 and drawing up said electrode through the threaded end 21 of its stem against thetop of disk 15 by means of a nut 22. This will seal the inner electrodes, while the flange 1'7 of the cap serves to seal the cell as a whole, and more securely than in the type wherein a gasket is utilized since there is eliminated the possibility of leakage between the gasket and disk. If, on the other hand, the rigid disk is of metal, only insulating bushings 23, Figs. 4 and 5, have to be added in case the electrodes 10 and 13 are intended to be insulated from each other.

In order to secure a vent for the gases which may develop in the cell, a further opening 25 is provided through the disk 15, and the bottom of the cap may be brought therein as in the form of a weakened tubular projection or riser 26 extendingtherethrough to the top of the disk to be readily accessible and puncturable when it is desired to place the cell in action. Or, as shownin Fig. 3, the cap 27 may be provided at the bottom with a fiat weakened portion 28 which may be readily pierced or will rupture automatically into the corresponding opening of the disk upon the application of suflicent pressure thereto from the interior of the cell. In the former embodiment, the opening made in the riser 26 (generally merely a pin hole) increases, though slowly, with increase of pressure developing in the cell, while in the case of a vent embodying the flattened weakened portion 28 the opening therein enlarges rapidly with such increase of pressure and is therefore more suitable inasmuch as it reduces the danger of explosion under abnormal operating conditions. The greater the area of the weakened portion, the more rapid will be the enla'rgement. of the pin hole opening which, in absence of a pressure, remains closed due to the inherent resiliency of the materiaL- In the provision of such weakened portion of the sealing cap, it becomes possible to dispense entirely with any and all constricted passageways, as generally employed; and thus allows of accommodating excessive pressures which sometimes develop in the operation of these con denser cells.

The rupturing operation may also be accomplished positively and automatically as the pres sure develops within the cell, said cell being normally sealed as is desirable for shipping purposes. For example, a metallic vent cap 30 having provided with an inwardly spring-fingers struck therefrom is designed to fit through the same into the opening 31 provided in opening, the same being more or less of a blade form to rapidly rupture the weakened portion 34 of the base of cap 35 when the same is brought into contact therewith by the development of sufficient pressure within the cell and which may occur gradually or, under certain conditions, suddenly as through heating of the condenser. In case of excessive pressure thus developing, the weakened portion itself is of such a nature that prevent damage to the cell. Where a plurality of electrodes are employed within the cell, the effect of any capacity existing therebetween is obviated by the provision of the grounding tabs; and proper contact therewith is insured by extending the tabs to the top of the cap member rather than turning the same under the crimping edge. This insures intimate contact with the shell as well as securelyretaining the tab so that it will not work loose; moreover, it reduces appreciably the chance for leakage.

I claim: p

1. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edge and directed support below said edge: a sealing cover member for the condenser carried by said support and comprising a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped \a considerableopening would develop therein and thereover to clampthe said cover member be- 2. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edgeand provided with an inwardly directed support below said edge: a sealing cover member for the condensercarried bysaid support and comprising a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk member, the top edge of the shell being adapted to be crimped thereover to clamp the cover member between it and the said support to effect a seal therebetween, and the said disk and cap being provided with registering electrode perforations, means to secure an electrode to the cover elements, and a flexible grounding tab connected with the shield of an electrode and extending over the side of the cap to be held between the same and the shell.

3. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edge and provided with an inwardly directed support below said edge: a sealing cover member for the 1,920,799 the support to effect a seal,

ber between it and therebetween, and the said disk and cap being provided with registering electrode perforations, a plurality of electrodes passing through the registering perforations provided therefor in the cover member and each having a flange for contacting with the base of the cap, and means at the top of the cover member flange against the cap base to thereat. i

4. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edge and provided with an inwardly directed support below said edge: a sealing cover member for the condenser carried by said support and comprising a disk of rigid material and an enveloping cap of elastic material covering entirely the innerface form a seal and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped thereover to clamp the said cover member between it and the support to effect a seal therebetween, and the said disk and cap being provided with registering. electrode perforations, means to secure an electrode to the cover elements, and a vent opening provided in the disk,

cooperating with a rupturable portion of the base of the cap.

5. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edge and provided with an inwardly directed support below said edge: a sealing cover member for the condenser carried by said support and comprising a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped thereover to clamp the said cover member between it and the support to effect a seal therebetween, and the said disk and cap being provided with registering electrode perforations, means to secure an electrode to the cover ele ments, and a vent opening provided in the disk cooperating with a rupturable portion of the base of the cap, the portion of the cap cooperating with the vent opening being of reduced thickness.

6. In an electrolytic condenser having a metal shell affording a container for the electrolyte, adapted to be turned over at its upper edge and provided with an inwardly directed support below said edge: a sealing cover member for the condenser carried by said support and comprising'a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped thereover to clamp the said cover member between it and the support to effect a seal therebetween, and the said disk and cap being provided with registering electrode perforations, means to secure an electrode to the cover elements, a vent opening provided in the disk cooperating with a rupturable portion of the base of the cap, said portion being of reduced thickness, and means carried by the disk to pierce automatically said rupturable portion as sufficient to draw said provided with registering electrode perforations,

gas pressure develops in the condenser to direct said rupturable portion into contact therewith.

7. In an electrolytic condenser having a metal shell afl'ording a container for the electrolyte, adapted to be turned over at its upper edge and provided with an inwardly directed support'below said edge: a sealing cover member for the condenser carried by said support and comprising a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped thereover to clamp the said cover member between it and the support to effect a seal therebetween, and the said disk and cap being provided with registering electrode perforations, means to secure an electrode to the cover elements, a vent opening provided in the disk cooperating with a rupturable portion of the base of the cap, said portion being of reduced t 'ckness, and an open vent plug having a sharpened portion adapted to puncture the rupturable portion as sufliclent gas pressure develops in the condenser to direct said rupturable portion into contact therewith.

8. In an electrolytic condenser having a metal shell affording a container for the electrolyte. adapted to be turned over at its upper edge and provided with an inwardly directed support below said edge: a sealing cover member for the condenser carried by said support and comprising a disk of rigid material, an enveloping cap of elastic material covering entirely the inner face and sides of the disk with inwardly turned flange extending partly over the outer face of the disk, the top edge of the cell being adapted to be crimped thereover to clamp the said cover member between it and the support to effect a seal therebetween, and the said disk and cap being means to secure an electrode to the cover elements, a vent opening provided in the disk cooperating with a rupturable portion of the base of the cap, said portion being of reduced thickness, and an open vent plug removably fitted into the disk and having a sharpened portion adapted to puncture the rupturable portion as suflicient gas pressure develops in the condenser to direct said rupturable portion into contact therewith.

9. An electrolytic condenser including a receptacle, an apertured cover for said receptacle fitting within the inner wall surface thereof and a flexible apertured diaphragm closing the aper ture of said cover, the apertures of said diaphragm being normally closed by the resiliency of the material, said diaphragm being positioned for flexing movement by pressure whereby the apertures thereof will be opened upon subjection of the diaphragm to pressure, said diaphragm exending over the edges of said cover and against the inner wall surfaces of the receptacle to form a gas-tight gasket therebetween.

10. An electrolytic condenser including a receptacle, an apertured cover therefor, a. normally closed breather diaphragm associated with said cover, said diaphragm extending over the edges of said cover and being crimped thereto by said receptacle, and electrodes extending through said cover and supported thereby. 

